How to ask the Jira dev team a question regarding Jira Software source code?

This came up while doing due diligence in porting our product to Jira 8.
We were reading Jira 8’s source code, and an important point came up that needs to be resolved with the Jira development team.

Previously, we could obtain assistance from Atlassian for issues regarding Jira and Marketplace at starting points like:

https://support.atlassian.com/browse/JSP-12345

These starting points no longer seem accessible. At least, all record of previous transactions are now met with HTTP 404s.

So, How is it done today? Where do we file an issue to get a response directly from the Jira dev team?

There is a ‘Developer Support’ option on the upper-right hand side of this very page.

Good point… none of the available request types seem to applicable to my request, but
I’ll try “Report a Bug” and see how far that goes.